Flatiron



' 1,636,359 July 19, 1927. E. GATES FLATIRON Filed DeG.'15. 1921 2Sheets-Sheet 1 E. GATES Y,

July 19,1927.` 1,636,359

FLAT I RON Filed Dec. 15. 1921 '2 sheets-,sheet 2 L A I Patented July19, 1927.

UNITED vSTATES PATENT OFFICE.

ELMER GATES, OF WASHINGTON, DISTRICT OFCOLUMBIA; DONALD E, GATES ADMIN-ISTRATOR OF SAID E1'| &IIERV GATES, DECEASED.

FLATIBON.

Application led December 15, 1921. Serial No. 522,552.

This invention relates to improvements in industrial heaters such asfrying pans, toasters, percolaters, ovens, electric flat irons,

and the like, and seeks,` as one of its prin-4 cipal objects, to providea heater which may be setto maintain its temperature within certainmaximum and minimum limits suitable to the particu-lar, work to `be donefor thus not only effecting a saving in heat energy consumed but alsoavoiding damage by overheating or i'nefliciency underheating as well aseliminating the anger of accidental fires through excessive temperature.A further object of the invention is to provide a heater wherein thewaste of heat by dissipation will `be reduced to a minimum and whereinoxidation of the heating element'with a consequent increase inresistivity will be overcome, thus making it possible to employdifferent resistances not. now practicable; f

The invention has as a still further object t provide a heater wherein auniform distribution of heat from the heating element will be had.

A still-further object is to provide a heater wher-ein the temperatureof the heating element will be controlled by the insulating medium for-said element and wherein said medium will be in direct contact with`-the working surface of the heater for transferring the heat generatedthereto.

The invention has as a further object to provide a heater wherein theinsulating medium will be of high heat conductivity so vthat the heatingelement needbe maintained at but aslightly higher temperature thanV theworking suface of the heater in order to heat said surface to thedesired degree and wherein, due to the conductivity of said medium,scorching by latent heat will be prevented by reason of the ability ofsaid medium to'cool quickly when the heating element is deenergizedbelow the scorching point of theworking surface.

And the invention has a still further object to provide a heater whichwill, in effect, embody a thermostat comprising an expanv sible mediumfor insulating the heating element, 'wherein the heat will be generatedby lthe element directly in said medium so that ractically all of theheat so generated will be utilized, wherein said medlum will serve totransfer the heat direct to the 'working surface of the heater, andwherein the expansion and contraction of said medium in volume willserve to regulate the Lempera- A Figure 3 is a fragmentary sectionalvie-w i on the line 3--3 of Figure 2, looking in the/ direction of thearrows,

Figure 4 is a vertical sectional view showing a slightly modified formof iron, and

Figure 5 is a vertical sectional view showing a still further modifiedform of iron.

Referring now more particularly to the drawings, I have, as previouslystated, shown the present invention embodied in a flat iron. The bod ofthe iron is indicated at 10 and formed t lerein near the bottom of theiron is a heating chamber 11 conforming in transverse configuration tothe shape of the bottom working face of the, iron, it bein observed thatonly a smallithickness lies tween the chamber and said face. On theother hand, above the chamber a disproportionate thickness of metal ispresent in order to provide the necessary weight* for the iron, andappropriately secured to the upper face of the body is a Suitable handle12. Threaded -through the wall of the chamber 11 is a switch plug 13provided near its inner end with a beveled face -14 toaov confront asimilar beveled face upon said wall and interposed between these facesis a circularly corrugated gasket 15 lwhich may be formed of lead. Thisconstruction provides 'an arrangement whereby the plug will hermeticallyseal the chamber. the plug may be otherwise connected to the ,body ofthe iron, if desired. As shown in Figure-2, the plug is tubular and iscounterbored at its outer end to provide an internal annular shoulder16. Fitting in the inner susv However,

in the rear of the diaphragm is apost 2O and pivoted at one end upon thebase of said post is a lever 21. Extending from the dlaphragm axiallythereof is a center stud 22 pivotally connected at its rear end with the`intermediate portion of the lever and mounted to rock upon the post atits upper end is a bell crank 23, the short arm of which is pivotallyconnected to the upper end of the lever. Near its'rear end, this bellcrank carries an upstanding switch blade 24. Threaded into thecounterbore at the rear end of the plug is a disc 25 provided with aplurality lof air passages 26 therethrough and overlying the inner faceof the disc is a line mesh wire screen 27 clam ed between the disc andthe shoulder 16.' he bell crank 23 is pointed at its rear end andthreaded through the disc is a regulating screw 28 having a pointedinner end to coact with the pointed end of the bell Lcrank. Threadedupon the plug at its rear s. or outer end is a closure cap 29 providedat yits inner side with an annular flange 30 abutting the disc 25 forrigidly bracing said disc and leading through the cap axially thereof isan elbow 31. Embedded in the inner face of the wall of the plug at itsupper side is a block 32 of suitable insulat- `elbow and through thedisc 25 `ing 36 into the channel 35 and surroun ing' material andmounted upon this block are switch poles 33 and 34 disposed to coactwith the switch blade 24. Leading forwardly through the wall of the plugfrom said block is a channel 35 preferably of the cross sectionalconfiguration shown in Figure 3, and entering t is channel near itsinner end is an opening 36. A feed cable 37 is a `propriately secured atits inner end in t e up er end of the elbow 31, a 38 eing employed forthe ca One wire 39 of this cable is led protecting coil through the andis connected to the switch pole 33. Leading from the switch pole 34through the channel 35 is a circuit wire 40. The other wire 41 of thecable is directed through one of the assages 26 in the disc and thenceythrough t e lo enthe wires 40 and 41 in said channelis closure plug 42for the channel. This plug may be of any ap ropriate material andhermetically sealst e channel at its inner end. Connected at its ends tothe wiresy 40 and 41 is a heatin Ielement 42 of suitable resistancewire. 'Ignis 'heating element is disposed within the chamber 11 of thebody of the iron and is protected by some suitable orous insulatingcovering so that shoul portions of the wire come in contact with eachother, short circuiting will not result. Interposed in the length of thewire is a fuse 43 and submer ing the wire is a fluid heating medium 44lling the chamber 11 to a level near the to thereof. .The heating medium44 is pre erably formed by a le, if desired.l

quantity of linseed oil and constitutes a liquid insulator for theheatin element 42. In assembling the iron, the oil 1s first heated to anappropriate temperature and is then introduced into the chamber 11 whenthe chamber is closed by the plug 13, the heating element 42 bein ofcourse, inserted in the chamber when t e plug is applied. Accordingly,when the oil cools, a vacuum will be established by the oil foraccommodating subsequent expansion of the oil under working conditionsof the iron.

As will now be seen, the heating lmedium 44 will be in direct contactwith the inner face of the working surface of the iron practicallylthroughout the entire area of said surface while the heating element 42will generate heat directl in said medium. Consequently, thedistrlbution of heat to the working surface of the iron will be uniformwhile a minimum of heat will be wasted. Furthermore, since the heatingmedium will be of high heat conductivity the heat generated therein willbe trans erred with rapidity to the working surface of the iron so thatthe heating element 42 need be maintained but slightly hotter than thedesired temperature of said surface while, due-to the rapld transfer ofheat through the heating medium, suliicient latent heat will not remainafter the current to the heating element has been cut off to causescorching at the-working surface of the iron. Since the heating elementis completely submerged, oxidation, with its consequent progressiveresistivity, will be largely overcome. Ac-

vcordingly, different resistance wires not now practicable, may beemployed in the presentL may not be as eiiicient'in producing eat forthe current consumed as a shorter wire at a higher temperature, still,no disadvantageis suffered by reason of the fact that I utilizepractically all of the heat generated and accordingly find incandescenceof the resistance W1re unnecessary.

Then the switch plate 24 is engaged with the switch poles 33 and 34 andthe switch is closed, current will, as will be at once appreciated,flowthrou h the heatin element 42 for energizing sai element am? heatingthe heating medium 44. yAs the temperature of the heating medium israised said heating medium will expand against the dia hra 17 forrockingI the lever 21 in a lrectlon tending to swlng the bell crank 23downelbow 31 and passages 26 in the disc 25.

Consequently, the lever 21 will be rocked in a direction tending toswing the bell *crank 23 upwardly and, as the edective atmosphericpressure against the diaphragm increases, the bell crank will be causedto snap over the inner end of the regulating screw 28 for returning theswitch blade 241:0 closed position cooperating with the switch poles.The circuit through the .heating element will accordingly be againclosed. Thus, the temperature of the iron will be automaticallymaintained 'within certain maximum and minimum limits so thatoverheating, with consequent danger and waste of current, will beavoided, while, at the same time, inefficiencyV due to underheating willalso be overcome. As will be seen2 the regulating screw 4ture ch 28maybe set for varying the maximum and minimum .temperatures of the 'ironto suit the work to be done and, if desired, an appropriate pointer anddial, not'shown, may be associated withv the screw whereby any desiredtemperature range may be easily selected. The screen 27 is provided as asafety device for reventing ignition of any gases about the p ace of useof the iron by a spark thrown o from the switch when being opened orclosed. Y

Attention is now directed to the fact that the heating medium 44constitutes the expan sible element of a thermostat and that expansionand contraction of said medium in volumeserves to control theenergization of the heating element. Furthermore, it will be seen thatthe heating medium mav be said to perform, in eiect, the actual thermicwork of the iron, being separate from the bottom smoothing surface ofthe iron only by a thin layer of metal. Accordingly, the' heating mediumwillbe directly Subjectedtdtemperawork of t iron and will, therefore,respond accurately, by expansionand contraction in volume, to saidchanges.y I thus provide an l eled set up by the performance of thearrangement wherein the expansible element of a thermostat isconstituted in aheating medium itself directly heated and dispose todirectly perform-in a practical sense, the thermicwork of the iron so asto thus be directly subjected to temperature changes incident to thework and consequently intimately reect said changes to regulate theheating of said medium. rIhe temperature of the working surface of theiron will thus be maintained relatively constant.

p In Figure 4 of he drawings, I have illustrated a slight modificationof the invention wherein the body of the iron is formed with a bottomsection 45 and a mating top section 46 fitting over the bottom section..At the joint between the sections, said sections are `preferably formedwith beveled faces and interposed between the sections is an appro-vpriate gasket 47. l `The top section is provided .centrally with anopening and Secured in said opening is a switch plug 48 similar to theplug 13 of the embodiment yof the invention previously described withthe exception that the plug 48 is provided with a lateral tube49'extending rearwardly alo top of the iron to receive the feed cab e-50. Otherwise, this modification is identical with the preferredconstruction.

the l In Figure 5 of the drawings, I have illusl trated a still furthermodification of the invention wherein the bod 'of the iron is pressedand is formed wit a sectionr 51 and ,a mating top section 52 similar tothe Sections 45 and 46 of the prior modification. At thejunctionbetweenthe sections av bevjoint is provided and interposed be--tween the sections is a gasket 53. Inorder to provide the necessaryweight for the iron,y a

block of metal 54 is appropriately secured to the top section and formedthrough this block as well as through saidY section is an opening toaccommodate a switch lug as in the modification previousl descri Havingthus described t e invention, what -is claimed as new is:

In a heater, the combination of a body pro- Lvided with a heatingchamber having a thin wall provided with al smoothing `faceand anopposite thick wall forming a weight for pressing said face against thework, a resistance in said chamber, and aheating medium in said chamberimmersing said resistance and directly in contact therewith.

.Inltestimony whereof I aix my signa- ELMER earns. [1.1]

